[Freeswitch-users] freeswitch and zrtp

Hi all, I'm deploying a ippbx with freeswitch and zrtp. It seems to work, but when i place a call i can't hear clean. It's impossible to understand what people say. I'm using tivi client for symbian s60. Both end have zrtp support (one unlimited and one passive licence). I also installed FS with zrtp support. Ccalls went to secure mode correctly but I can't hear nothing. I tried to install another FS, I get this error: switch_rtp.c:2122 Error: zRTP protection drop with code 9. I'm a little desperate :-) Any similar experience or possible solutions?